U.S. JOINS IN PACT ON ATOMIC CURBS WITH 6 COUNTRIES
US Arms Control and Disarmament Agency Dir Fred C Ikle, in Feb 23 testimony before Sen Foreign Relations subcom on arms control, discloses that US and 6 other major indus countries, to discourage spread of atomic weapons, have concluded secret agreement to cooperate in developing new safeguards and controls on export of nuclear facilities; does not name other countries, but they are known to be USSR, GB, W Ger, France, Japan and Canada; had earlier declined to give names to Sen Stuart Symington; State Dept official says other countries, notably France, had placed restriction on disclosure of details; agreement worked out in meetings in London, prompted partly by India's detonation of nuclear device in '74; Ikle notes agreement provisions, designed to inhibit spread of weapons while permitting export of equipment to meet world's growing energy needs; one is application of safeguards drawn up by Internatl Atomic Energy Agency; Ikle por (M)